pop_list()

Kind of a misnomer, you have to take the tail() of the stack yourself.
This function only returns the list from TOS.

diff --git a/implementations/uvm-ncc/joy.c b/implementations/uvm-ncc/joy.c
index 4dff1dd..360cd2b 100644 (file)
--- a/implementations/uvm-ncc/joy.c
+++ b/implementations/uvm-ncc/joy.c
@@ -555,8 +555,9 @@ joy_eval(char *symbol, u32 stack, u32 expression)
        return (u64)stack << 32 | expression;
 }
 
-u64
-swaack(u32 stack, u32 expression)
+
+u32
+pop_list(u32 stack)
 {
        if (!stack) {
                error = NOT_ENOUGH_VALUES_ON_STACK;
@@ -567,6 +568,15 @@ swaack(u32 stack, u32 expression)
                error = NOT_A_LIST;
                return 0;
        }
+       return list;
+}
+
+
+u64
+swaack(u32 stack, u32 expression)
+{
+       u32 list = pop_list(stack);
+       CHECK_ERROR
        stack = cons(tail(stack), list);
        CHECK_ERROR
        return (u64)stack << 32 | expression;